28086321 has 4 divisors (see below), whose sum is σ = 37448432. Its totient is φ = 18724212.

The previous prime is 28086319. The next prime is 28086371. The reversal of 28086321 is 12368082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 28086321 - 2¹ = 28086319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28086371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4681051 + ... + 4681056.

It is an arithmetic number, because the mean of its divisors is an integer number (9362108).

Almost surely, 2^28086321 is an apocalyptic number.

It is an amenable number.

28086321 is a deficient number, since it is larger than the sum of its proper divisors (9362111).

28086321 is an equidigital number, since it uses as much as digits as its factorization.

28086321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9362110.

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 28086321 is about 5299.6529131633. The cubic root of 28086321 is about 303.9706263459.

The spelling of 28086321 in words is "twenty-eight million, eighty-six thousand, three hundred twenty-one".